Electric glow-lamp.



W. NERNST.

ELECTRIC GLOW LAMP.

APPLICATION FILED DEO.19, 1906 1,071,649, Patented 'Aug. 26, 1913.

W/TNESSES INSVENTOI? COLUMBIA PLANOGRAPH CO.,WASNINGTON, n. c.

UNITED STATES PATENT FFICE.

WALTHER NERNST, 0F-GOTTINGEN, GERMANY, ASSIGNOR, BY MESNE ASSIGNMENTS, TO NERNST LAMP COMPANY, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

Patented A11 26,1913.

Original application filed March 29, 1898, Serial No. 675,603. Divided and this application filed December 19, 1906. Serial No. 348,567.

To all whom it may concern:

Be it known that I, WVALTHER NERNsT, a subject of the German Emperor, and resident of Gottingen, in the Kingdom of Prussia, German Empire, have invented certain new and useful Improvements in Electric Glow-Lamps, of which the following is a specification.

My invention relates to the class of electric lamps in which the light-emitting element is a non-conductor at ordinary temperatures and which may be made conductive by subjecting it to a relatively high degree of heat.

My present invention relates particularly to such light-emitting elements or glowers composed of one or more of the rare earths mixed with other materials and also to the process of making and using the same.

I have found that mixtures of the proper materials produce a glower which will become conductive at a lower temperature than glowers made of one material alone. In preparing the glowers the materials are thoroughly powdered and mixed together, and then moistened by any suitable binding material. They are afterward formed into the proper shape and thoroughly baked. Suitable terminals of conductin material are attached to the ends thereof, and they are thus adapted to be connected into an electric circuit.

As an example of a mixture suitable for forming glowers, I may mention a combination of magnesia with a small percentage of boric acid, chlorid of calcium, tungstic acid, or the like. A glower formed of such a mixture of materials will operate on a pressure of 100 volts at the terminals of the glower, while the amount of heat required to render the glower conductive will be small, such for example, as would be given out by the flame of a match.

Any convenient means for rendering the glower conductive by means of heat may be employed, such for instance, as described in my Patent Number 623,811, dated April 25, 1899, or an electric heater such as described in my Patent Number 685,725, issued October 29, 1901. lVhen such a glower is connected in an electric circuit and brought to its conducting temperature, the heat developed within itself by the passage of the current therethrough will serve to maintain it in a conductive condition, and cause it to yield light in a very efficient manner.

As an illustration of my invention I show in the drawing a glower, 1, formed of a mixture of materials, which mixture is nonconducting when cold. As a simple means of illustrating the heating device I show a torch, 2, supported upon a suitable base, 8.

This application is a division of application Serial Number 675,603, filed March 29, 1898, and which has issued as Patent 900,416, dated October 6, 1908, and other divisions thereof are applications Serial Number 452,485, filed September 10, 1908, and Serial Number 763,184, filed April 24, 1913, and claims are therein made upon certain features described herein.

I claim as my invention:

1. An illuminant for incandescent electric lamps containing a tungsten compound and a normally non-conducting material.

2. A glower for incandescent electric lamps, consisting of intimately mixed rare earth and a small percentage of tungstic acid, substantially as described.

3. A glow'er for electric lights, consisting of an intimate mixture of magnesia, and a small percentage of tungstic acid.

Signed at New York, in the county of New York, and State of New York, this 5th day of November, A. D. 1906.

WALTI-IER NERNST.

Witnesses:

ROBERT MoLEoD JAoKsoN, GEORGE H. STOCKBRIDGE.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

